Stork watch: Kristen Bell and Dax Shepard are expecting a baby

Surprise a woman with a sloth, and she's putty in your hands. People magazine reports Kristen Bell and Dax Shepard are awaiting their first delivery from the stork.

The bundle of joy is expected to arrive in the spring, confirms their rep.

"They're so excited," a source tells the mag. "They're both ecstatic. They can't wait to become parents."

The insider says the actress “had a little bit of morning sickness early on, but she just started shooting the second season of 'House of Lies' and is feeling great now.”

Bell, 32, and Shepard, 37, began dating in 2007, and he popped the question in January 2010. In an August interview with Larry King, Kristen explained that they were waiting to get hitched until everyone had the right.

"I'll feel more comfortable having a party -- or whatever we have, if anything -- if half of our friends who are homosexuals [can celebrate]," said the once (and hopefully future) "Veronica Mars." "It's just kind of rude to invite everyone to a party for a right not everyone can hold."

During the same interview, she and Shepard declared their intention to be fruitful and multiply.

"We'll have them out of wedlock," predicted Dax. "We're not worried about that."

Not that the relationship hasn't had its share of stresses.

"Kristen's a good girl," Shepard told Playboy in September. "She grew up very Christian, went straight to college, did great in school and started work immediately. She's charitable and philanthropic and rescues dogs."

Because of that, "All the things I'd done were terrifying to her," acknowledged the onetime hard partier, "and she had a hard time believing I would ever be able to stay married and monogamous and a father and all those things."

Clearly, she came around, but "for the first year and a half we were together," Dax said, "that was what we battled over almost weekly."